The HTS (High Tip Speed) assembly has a gearbox with a circular boss as
part of the casting. This boss fit into the tail boom and was secured
with 10-32 capscrews that went through the tail boom radially. The
blades were quite small compared to the LTS hardware. The army
complained about a lack of tail rotor authority when using the 269A
(TH55) for training. The solution was an adapter that replaced the HTS
gearbox and provided a mounting surface that was perpendicular to the
tail boom centerline. They then took the tail rotor gearbox and blade
assembly from the 369 series (500C) and along with a new tail rotor
driveshaft and control rod and now had a tail rotor that rotated slower
and had more effect. There were several other parts (such as the rear
airfoil) that were also replaced. This was all available as a kit which
was field installable.

I flew my 269A (with maybe the only surviving HTS assembly) for 500 plus
hours without any problems. The HTS assembly had a distinct buzzing
sound that could be hear early in the heli's approach. I don't recall
the difference in the tail rotor speed (the tail rotor gearbox had a
different ratio), but it was significant.

I have pictures of the HTS assembly on my ship if they would be of any
help. The Hughes manuals (maintenance and parts) still covered both
setups even though parts weren't available from Hughes (or later
Schweizer). If you need any more info, just let me know.

Gary

Stuart & Kathryn Fields wrote:
"gk" wrote in message
...

Brien wrote:
What are the advantages of the LTS over the HTS.
Quieter and better tail rotor authority. Also, HTS parts are really
scarce and not produced anymore.

Gary

Where can I find a description of what makes one an LTS and what makes one
an HTS? I have never heard of this distinction before.